MiR-302b as a Combinatorial Therapeutic Approach to Improve Cisplatin Chemotherapy Efficacy in Human Triple-Negative Breast Cancer

Integrins as the pivotal regulators of cisplatin response in tumor cells

Cisplatin (CDDP) is a widely used first-line chemotherapeutic drug in various cancers. However, CDDP resistance is frequently observed in cancer patients. Therefore, it is required to evaluate the molecular mechanisms associated with CDDP resistance to improve prognosis among cancer patients. Integrins are critical factors involved in tumor metastasis that regulate cell-matrix and cell-cell interactions. They modulate several cellular mechanisms including proliferation, invasion, angiogenesis, polarity, and chemo resistance. Modification of integrin expression levels can be associated with both tumor progression and inhibition. Integrins are also involved in drug resistance of various solid tumors through modulation of the tumor cell interactions with interstitial matrix and extracellular matrix (ECM). Therefore, in the present review we discussed the role of integrin protein family in regulation of CDDP response in tumor cells. It has been reported that integrins mainly promoted the CDDP resistance through interaction with PI3K/AKT, MAPK, and WNT signaling pathways. They also regulated the CDDP mediated apoptosis in tumor cells. This review paves the way to suggest the integrins as the reliable therapeutic targets to improve CDDP response in tumor cells.

Cisplatin-Based Combination Therapy for Enhanced Cancer Treatment

Cisplatin, a primary chemotherapeutic drug, is of great value in the realm of tumor treatment. However, its clinical efficacy is strictly hindered by issues, such as drug resistance, relapse, poor prognosis, and toxicity to normal tissue. Cisplatin-based combination therapy has garnered increasing attention in both preclinical and clinical cancer research for its ability to overcome resistance, reduce toxicity, and enhance anticancer effects. This review examines three primary co-administration strategies of cisplatin-based drug combinations and their respective advantages and disadvantages. Additionally, seven types of combination therapies involving cisplatin are discussed, focusing on their main therapeutic effects, mechanisms in preclinical research, and clinical applications. This review also discusses future prospects and challenges, aiming to offer guidance for the development of optimal cisplatin-based combination therapy regimens for improved cancer treatment.

PCMT1 knockdown attenuates malignant properties by globally regulating transcriptome profiles in triple-negative breast cancer cells

Background

As the most frequently diagnosed cancer in women, Breast cancer has high mortality and metastasis rate, especially triple-negative breast cancer (TNBC). As an oncogene, protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) is a prognostic biomarker in breast cancer and is highly expressed, while its underlying functions remain unknown.

Methods

In this study, we silenced PCTM1 in TNBC MDA-MB-231 cells by short hairpin RNA (shPCMT1) to investigate its cellular functions using cell proliferation, apoptosis, migration, and invasion experiments. Following this, the transcriptome sequencing (RNA-seq) experiment was conducted to explore the molecular targets of PCMT1, including differentially expressed genes (DEGs) and regulated alternative splicing events (RASEs).

Results

The results showed that shPCMT1 inhibited the proliferation, migration, and invasion of MDA-MB-231 cells. We obtained 1,084 DEGs and 2,287 RASEs between shPCMT1 and negative control (NC) groups through RNA-seq. The DEGs were significantly enriched in immune or inflammation response and cell adhesion-associated pathways, pathways associated with PCMT1 cellular function in cell migration. The RASE genes were enriched in cell cycle-associated pathways and were associated with the altered cell proliferation rate. We finally validated the changed expression and splicing levels of DEGs and RASEs. We found that 34 RNA binding protein (RBP) genes were dysregulated by shPCMT1, including NQO1, S100A4, EEF1A2, and RBMS2. The dysregulated RBP genes could partially explain how PCMT1 regulates the global transcriptome profiles.

Conclusion

In conclusion, our study identified the molecular targets of PCMT1 in the TNBC cell line, expands our understanding of the regulatory mechanisms of PCMT1 in cancer progression, and provides novel insights into the progression of TNBC. The identified molecular targets are potential therapeutic targets for future TNBC treatment.

The miR-302/367 cluster: Aging, inflammation, and cancer

MicroRNAs (miRNAs) are a class of noncoding RNAs that occupy a significant role in biological processes as important regulators of intracellular homeostasis. First, we will discuss the biological genesis and functions of the miR-302/367 cluster, including miR-302a, miR-302b, miR-302c, miR-302d, and miR-367, as well as their roles in physiologically healthy tissues. The second section of this study reviews the progress of the miR-302/367 cluster in the treatment of cancer, inflammation, and diseases associated with aging. This cluster's aberrant expression in cells and/or tissues exhibits similar or different effects in various diseases through molecular mechanisms such as proliferation, apoptosis, cycling, drug resistance, and invasion. This article also discusses the upstream and downstream regulatory networks of miR-302/367 clusters and their related mechanisms. Particularly because studies on the upstream regulatory molecules of miR-302/367 clusters, which include age-related macular degeneration, myocardial infarction, and cancer, have become more prevalent in recent years. MiR-302/367 cluster can be an important therapeutic target and the use of miRNAs in combination with other molecular markers may improve diagnostic or therapeutic capabilities, providing unique insights and a more dynamic view of various diseases. It is noted that miRNAs can be an important bio-diagnostic target and offer a promising method for illness diagnosis, prevention, and treatment.

Regulation and Functions of α6-Integrin (CD49f) in Cancer Biology

Over the past decades, our knowledge of integrins has evolved from being understood as simple cell surface adhesion molecules to receptors that have a complex range of intracellular and extracellular functions, such as delivering chemical and mechanical signals to cells. Consequently, they actively control cellular proliferation, differentiation, and apoptosis. Dysregulation of integrin signaling is a major factor in the development and progression of many tumors. Many reviews have covered the broader integrin family in molecular and cellular studies and its roles in diseases. Nevertheless, further understanding of the mechanisms specific to an individual subunit of different heterodimers is more useful. Thus, we describe the current understanding of and exploratory investigations on the α6-integrin subunit (CD49f, VLA6; encoded by the gene itga6) in normal and cancer cells. The roles of ITGA6 in cell adhesion, stemness, metastasis, angiogenesis, and drug resistance, and as a diagnosis biomarker, are discussed. The role of ITGA6 differs based on several features, such as cell background, cancer type, and post-transcriptional alterations. In addition, exosomal ITGA6 also implies metastatic organotropism. The importance of ITGA6 in the progression of a number of cancers, including hematological malignancies, suggests its potential usage as a novel prognostic or diagnostic marker and useful therapeutic target for better clinical outcomes.

Regulation of Inflammasome by microRNAs in Triple-Negative Breast Cancer: New Opportunities for Therapy

During the past decade, researchers have investigated the molecular mechanisms of breast cancer initiation and progression, especially triple-negative breast cancer (TNBC), in order to identify specific biomarkers that could serve as feasible targets for innovative therapeutic strategies development. TNBC is characterized by a dynamic and aggressive nature, due to the absence of estrogen, progesterone and human epidermal growth factor 2 receptors. TNBC progression is associated with the dysregulation of nucleotide-binding oligomerization domain-like receptor and pyrin domain-containing protein 3 (NLRP3) inflammasome, followed by the release of pro-inflammatory cytokines and caspase-1 dependent cell death, termed pyroptosis. The heterogeneity of the breast tumor microenvironment triggers the interest of non-coding RNAs' involvement in NLRP3 inflammasome assembly, TNBC progression and metastasis. Non-coding RNAs are paramount regulators of carcinogenesis and inflammasome pathways, which could help in the development of efficient treatments. This review aims to highlight the contribution of non-coding RNAs that support inflammasome activation and TNBC progression, pointing up their potential for clinical applications as biomarkers for diagnosis and therapy.

The Role of MicroRNAs in HER2-Positive Breast Cancer: Where We Are and Future Prospective

Simple Summary

Breast cancer is the most diagnosed malignancy in woman worldwide and, despite the availability of new innovative therapies, it remains the first cause of death for tumor in woman. 20% of all breast cancer cases are HER2 positive, meaning that they are characterized by an aberrant expression of the growth factor receptor HER2. This receptor is involved in survival and proliferation mechanisms, conferring to this breast cancer subtype a particular aggressiveness. The introduction of anti-HER2 agents, such as trastuzumab, in the clinical practice, significantly improved the prognosis. However, a great portion of patients is not responsive to this therapy. Thus, cancer research is working to provide new tools to better manage HER2 positive breast cancers, such as biomarkers and therapeutic approaches. MicroRNAs could be used for these purposes. They are small molecules involved in almost all biological processes, including cancer promoting pathways. Researchers consider microRNAs as promising clinical tools because they are easily detectable and stable in both tissues and blood samples, and an increasing body of evidence supports their potential use as targets of therapy, prognostic and predictive biomarkers, or therapeutic agents. This review sums up the most recent scientific publications about microRNAs in HER2 positive breast cancer.

Abstract

Breast cancer that highly expresses human epidermal growth factor receptor 2 (HER2+) represents one of the major breast cancer subtypes, and was associated with a poor prognosis until the introduction of HER2-targeted therapies such as trastuzumab. Unfortunately, up to 30% of patients with HER2+ localized breast cancer continue to relapse, despite treatment. MicroRNAs (miRNAs) are small (approximately 20 nucleotides long) non-coding regulatory oligonucleotides. They function as post-transcriptional regulators of gene expression, binding complementarily to a target mRNA and leading to the arrest of translation or mRNA degradation. In the last two decades, translational research has focused on these small molecules because of their highly differentiated expression patterns in blood and tumor tissue, as well as their potential biological function. In cancer research, they have become pivotal for the thorough understanding of oncogenic biological processes. They might also provide an efficient approach to early monitoring of tumor progression or response to therapy. Indeed, changes in their expression patterns can represent a flag for deeper biological changes. In this review, we sum up the recent literature regarding miRNAs in HER2+ breast cancer, taking into account their potential as powerful prognostic and predictive biomarkers, as well as therapeutic tools.

Integrated bioinformatics and statistical approaches to explore molecular biomarkers for breast cancer diagnosis, prognosis and therapies

Integrated bioinformatics and statistical approaches are now playing the vital role in identifying potential molecular biomarkers more accurately in presence of huge number of alternatives for disease diagnosis, prognosis and therapies by reducing time and cost compared to the wet-lab based experimental procedures. Breast cancer (BC) is one of the leading causes of cancer related deaths for women worldwide. Several dry-lab and wet-lab based studies have identified different sets of molecular biomarkers for BC. But they did not compare their results to each other so much either computationally or experimentally. In this study, an attempt was made to propose a set of molecular biomarkers that might be more effective for BC diagnosis, prognosis and therapies, by using the integrated bioinformatics and statistical approaches. At first, we identified 190 differentially expressed genes (DEGs) between BC and control samples by using the statistical LIMMA approach. Then we identified 13 DEGs (AKR1C1, IRF9, OAS1, OAS3, SLCO2A1, NT5E, NQO1, ANGPT1, FN1, ATF6B, HPGD, BCL11A, and TP53INP1) as the key genes (KGs) by protein-protein interaction (PPI) network analysis. Then we investigated the pathogenetic processes of DEGs highlighting KGs by GO terms and KEGG pathway enrichment analysis. Moreover, we disclosed the transcriptional and post-transcriptional regulatory factors of KGs by their interaction network analysis with the transcription factors (TFs) and micro-RNAs. Both supervised and unsupervised learning's including multivariate survival analysis results confirmed the strong prognostic power of the proposed KGs. Finally, we suggested KGs-guided computationally more effective seven candidate drugs (NVP-BHG712, Nilotinib, GSK2126458, YM201636, TG-02, CX-5461, AP-24534) compared to other published drugs by cross-validation with the state-of-the-art alternatives top-ranked independent receptor proteins. Thus, our findings might be played a vital role in breast cancer diagnosis, prognosis and therapies.

Inhibiting L1CAM Reverses Cisplatin Resistance of Triple Negative Breast Cancer Cells by Blocking AKT Signaling Pathway

DDP-resistant MDA-MB-231 cells (MDA-MB-231/DDP) cells had higher expression of L1CAM than their parental cells. L1CAM siRNA decreased the IC50 of MDA-MB-231/DDP cells to DDP. L1CAM inhibition down-regulated p-AKT/AKT in MDA-MB-231/DDP cells; meanwhile, it could promote MDA-MB-231/DDP cell apoptosis, inhibit cell EMT, invasion, and migration. Moreover, SC79 (an AKT activator) increased the DDP-resistance of MDA-MB-231/DDP cells, which was reversed by L1CAM inhibition. Furthermore, co-treatment of L1CAM shRNA and cisplatin injection had better anti-tumor effects in vivo than these two single treatments with decreased p-AKT/AKT. Thus, silencing L1CAM reversed the DDP resistance by inhibiting the AKT pathway.

MicroRNA-485-5p inhibits glioblastoma progression by suppressing E2F transcription factor 1 under cisplatin treatment

Cisplatin (CDDP) has been widely used for glioblastoma treatment. miR-485-5p and E2F transcription factor 1 (E2F1) dysfunction has been reported in glioblastoma. Nonetheless, whether CDDP affects glioblastoma progression via the miR-485-5p-E2F1 axis requires investigation. The expression of miR-485-5p and E2F1 was investigated by quantitative real-time polymerase chain reaction or western blotting in glioblastoma tissues and cell lines. The interaction between miR-485-5p and E2F1 was confirmed using a luciferase assay. The malignancy of glioblastoma was detected using Cell Counting Kit-8, bromodeoxyuridine (BrdU), cell adhesion, flow cytometry, and transwell assays. We identified miR-485-5p downregulation and E2F1 upregulation in glioblastoma, and miR-485-5p inhibited cell growth and elevated cell apoptosis in glioblastoma cells after CDDP treatment. Moreover, miR-485-5p targeting E2F1 repressed cell growth and improved cell apoptosis in glioblastoma cells after CDDP treatment. Our study revealed that CDDP retarded glioblastoma cell development via the miR-485-5p-E2F1 axis, which may be a new direction for glioblastoma therapy.

Breast Cancer Drug Resistance: Overcoming the Challenge by Capitalizing on MicroRNA and Tumor Microenvironment Interplay

The clinical management of breast cancer reaches new frontiers every day. However, the number of drug resistant cases is still high, and, currently, this constitutes one of the major challenges that cancer research has to face. For instance, 50% of women affected with HER2 positive breast cancer presents or acquires resistance to trastuzumab. Moreover, for patients affected with triple negative breast cancer, standard chemotherapy is still the fist-line therapy, and often patients become resistant to treatments. Tumor microenvironment plays a crucial role in this context. Indeed, cancer-associated stromal cells deliver oncogenic cues to the tumor and vice versa to escape exogenous insults. It is well known that microRNAs are among the molecules exploited in this aberrant crosstalk. Indeed, microRNAs play a crucial function both in the induction of pro-tumoral traits in stromal cells and in the stroma-mediated fueling of tumor aggressiveness. Here, we summarize the most recent literature regarding the involvement of miRNAs in the crosstalk between tumor and stromal cells and their capability to modulate tumor microenvironment characteristics. All up-to-date findings suggest that microRNAs in the TME could serve both to reverse malignant phenotype of stromal cells, modulating response to therapy, and as predictive/prognostic biomarkers.

miR-92b-3p Regulates Cell Cycle and Apoptosis by Targeting CDKN1C, Thereby Affecting the Sensitivity of Colorectal Cancer Cells to Chemotherapeutic Drugs

Simple Summary

Multidrug resistance (MDR) limits the effectiveness of colorectal cancer (CRC) treatment and miRNAs play an important role in drug resistance. To search for miRNA targets that may be involved in the CRC MDR phenotype, this study used small RNAomic screens to analyze the expression profiles of miRNAs in CRC HCT8 cell line and its chemoresistant counterpart HCT8/T cell line. It was found that miR-92b-3p was highly expressed in HCT8/T cells and chemotherapeutic drugs could stimulate CRC cells to up-regulate miR-92b-3p expression and conferred cellular resistance to chemotherapeutic drugs. This study revealed a new mechanism of MDR in CRC, elucidating for the first time the direct link between miR-92b-3p/CDKN1C and chemoresistance. In summary, this study suggested that miR-92b-3p could be used as a potential therapeutic target for reversing MDR in chemotherapy and as a candidate biomarker for predicting the efficacy of chemotherapy.

Abstract

Colorectal cancer (CRC) is the third most common malignant tumor in the world and the second leading cause of cancer death. Multidrug resistance (MDR) has become a major obstacle in the clinical treatment of CRC. The clear molecular mechanism of MDR is complex, and miRNAs play an important role in drug resistance. This study used small RNAomic screens to analyze the expression profiles of miRNAs in CRC HCT8 cell line and its chemoresistant counterpart HCT8/T cell line. It was found that miR-92b-3p was highly expressed in HCT8/T cells. Knockdown of miR-92b-3p reversed the resistance of MDR HCT8/T cells to chemotherapeutic drugs in vitro and in vivo. Paclitaxel (PTX, a chemotherapy medication) could stimulate CRC cells to up-regulate miR-92b-3p expression and conferred cellular resistance to chemotherapeutic drugs. In studies on downstream molecules, results suggested that miR-92b-3p directly targeted Cyclin Dependent Kinase Inhibitor 1C (CDKN1C, which encodes a cell cycle inhibitor p57Kip2) to inhibit its expression and regulate the sensitivity of CRC cells to chemotherapeutic drugs. Mechanism study revealed that the miR-92b-3p/CDKN1C axis exerted a regulatory effect on the sensitivity of CRC cells via the regulation of cell cycle and apoptosis. In conclusion, these findings showed that miR-92b-3p/CDKN1C was an important regulator in the development of drug resistance in CRC cells, suggesting its potential application in drug resistance prediction and treatment.

The Antioxidant Carrichtera annua DC. Ethanolic Extract Counteracts Cisplatin Triggered Hepatic and Renal Toxicities

Cisplatin is a powerful anti-neoplastic drug that displays multi-organ toxicity, especially to the liver and kidneys. Consumption of phytomedicines is a promising strategy to overcome the side effects of chemotherapy. Carrichtera annua extract proved to possess potent antioxidant activity. Its protective potential against cisplatin-induced hepato-nephrotoxicity was scrutinized. Moreover, a phytochemical study was conducted on C. annua ethyl acetate fraction which led to the isolation of five known phenolic compounds. Structure determination was achieved utilizing 1H- and 13C-NMR spectral analyses. The isolated phytochemicals were trans-ferulic acid (1), kaempferol (2), p-coumaric acid (3), luteolin (4) and quercetin (5). Regarding our biological study, C. annua has improved liver and kidney deteriorated functions caused by cisplatin administration and attenuated the histopathological injury in their tissues. Serum levels of ALT, AST, blood urea nitrogen and creatinine were significantly decreased. C. annua has modulated the oxidative stress mediated by cisplatin as it lowered MDA levels while enhanced reduced-GSH concentrations. More importantly, the plant has alleviated cisplatin triggered inflammation, apoptosis via reduction of INFγ, IL-1β and caspase-3 production. Moreover, mitochondrial injury has been ameliorated as remarkable increase of mtDNA was noted. Furthermore, the MTT assay proved the combination of cisplatin-C. annua extract led to growth inhibition of MCF-7 cells in a notable additive way. Additionally, we have investigated the binding affinity of C. annua constituents with caspase-3 and IFN-γ proteins using molecular simulation. All the isolated compounds exhibited good binding affinities toward the target proteins where quercetin possessed the most auspicious caspase-3 and IFN-γ inhibition activities. Our results put forward that C. annua is a promising candidate to counteract chemotherapy side effects and the observed activity could be attributed to the synergism between its phytochemicals.

miR-9-Mediated Inhibition of EFEMP1 Contributes to the Acquisition of Pro-Tumoral Properties in Normal Fibroblasts

Tumor growth and invasion occurs through a dynamic interaction between cancer and stromal cells, which support an aggressive niche. MicroRNAs are thought to act as tumor messengers to “corrupt” stromal cells. We previously demonstrated that miR-9, a known metastamiR, is released by triple negative breast cancer (TNBC) cells to enhance the transition of normal fibroblasts (NFs) into cancer-associated fibroblast (CAF)-like cells. EGF containing fibulin extracellular matrix protein 1 (EFEMP1), which encodes for the ECM glycoprotein fibulin-3, emerged as a miR-9 putative target upon miRNA’s exogenous upmodulation in NFs. Here we explored the impact of EFEMP1 downmodulation on fibroblast’s acquisition of CAF-like features, and how this phenotype influences neoplastic cells to gain chemoresistance. Indeed, upon miR-9 overexpression in NFs, EFEMP1 resulted downmodulated, both at RNA and protein levels. The luciferase reporter assay showed that miR-9 directly targets EFEMP1 and its silencing recapitulates miR-9-induced pro-tumoral phenotype in fibroblasts. In particular, EFEMP1 siRNA-transfected (si-EFEMP1) fibroblasts have an increased ability to migrate and invade. Moreover, TNBC cells conditioned with the supernatant of NFs transfected with miR-9 or si-EFEMP1 became more resistant to cisplatin. Overall, our results demonstrate that miR-9/EFEMP1 axis is crucial for the conversion of NFs to CAF-like cells under TNBC signaling.